This invention relates to an improvement in the trigger device of an automatic gun.
In an automatic gun, a gas pressure developed when it is fired is utilized to cause a breech block inside a receiver to retract. The rearward movement of the breech block ejects a shell remaining in a barrel chamber. Then, concurrently with this ejection, the breech block moves forward to cause the next cartridge to come out from inside of a magazine to load the chamber therewith. Following this, a pulling action on a trigger causes a firing pin to be hit by a quick rotational uprising action of a hammer for next firing. After the firing, the hammer is again brought back to its initial position through the rearward movement of the breech block inside the receiver to complete preparation for further firing.
The above stated series of actions for automatic loading are performed in an extremely short period of time after firing a cartridge. Hence, a beginner shooter often continues to pull the trigger until next firing become ready after firing. Such continuous pulling tends to cause spontaneous firing of a cartridge. Thus, it has been necessary to have a safety mechanism for preventing such a spontaneous firing accident.
Accordingly, there have been provided many kinds of such safety mechanism including for example; a mechanism wherein a trigger is provided with two stages of hammer locking arrangement. The hammer is locked at first stage when it is tilled by the rearward movement of a breech block. Following this, when a trigger is released by a shooter's finger grip, the hammer locking is shifted to a second stage. In another example, a hammer is locked in a tilting state by a sear. Then, the hammer is released from the sear by a forward movement of a connector which takes place in response to a trigger. After firing, the connector is released from an interlocked relation to the sear by a certain mechanism until the breech block which moves back and forth inside a receiver comes back to its initial position. Of these known prior art safety arrangements, the former lacks interrelation between the forward movement of the breech block and shifting from one hammer locking position to another. As a result, spontaneous firing of a cartridge might take place if the hammer along happens to shift to the second locking stage during a loading and unloading of a cartridge. In the case of the latter, the safety is secured because of the arrangement not to complete preparation for firing until the breech block comes to its initial position. However, the arrangement for a continued release of the connector from the interlocked relation to the sear based on a pushing force of a hammer spring for rotative uprising of the hammer and the movement of a carrier in a cartridge operating mechanism results in a complex structure and thus causes an increase in the number of parts required. With such arrangement, therefore, the manufacturing cost increases.